Resistance training predicts 6-yr body composition change in postmenopausal women.

PURPOSE: The aim of this study was to examine the association of exercise frequency (ExFreq) and volume (total weight lifted by military press and squats (SQ)) with change in body composition among postmenopausal women participating in a progressive resistance training study. METHODS: Previously, sedentary women (n = 122, age = 56.3 +/- 4.3 yr) were followed for 6 yr. At 6 yr, there were women who had been randomly assigned to resistance training at baseline (n = 65) controls that were permitted to cross over to the exercise program at 1 yr (n = 32) and 25 true controls. Exercisers and crossovers directed to perform eight core exercises for two sets of eight repetitions at 70%-80% of one-repetition maximum, three times weekly, plus progressive weight bearing, stretching, and balance. Body weight and fat were measured at baseline and annually using anthropometry and dual-energy x-ray absorptiometry. RESULTS: Average change in body weight and total body fat were 0.83 +/- 5.39 and 0.64 +/- 4.95 kg at 6 yr, respectively. In multiple linear regression, ExFreq, military press, and SQ were significantly inversely associated with change in body weight (standardized beta coefficient (SBC) = -0.22 to -0.28, P < 0.01), fat (SBC = -0.25 to -0.33, P < 0.01), and trunk fat (SBC = -0.20 to -0.31, P < 0.03) after adjusting for age, years on hormone therapy, change in lean soft tissue, baseline body composition, and baseline habitual exercise. The lowest tertile of SQ (equivalent to 2.5% attendance) demonstrated significant gain in weight, fat, and trunk fat over 6 yr (P < 0.004), whereas the highest tertile SQ (equivalent to 64% attendance) was able to maintain their weight, total, and regional fat. CONCLUSIONS: We conclude that resistance training is a viable long-term method to prevent weight gain and deleterious changes in body composition in postmenopausal women.

Mediators affecting girls' levels of physical activity outside of school: findings from the trial of activity in adolescent girls.

BACKGROUND: Providing after school activities is a community level approach for reducing the decline in physical activity of girls as they reach early adolescence. PURPOSE: The purpose of this study was to examine psychosocial, environmental, and behavioral factors as potential mediators of after school physical activity in adolescent girls. METHODS: We assessed objectively measured levels of physical activity occurring outside of school and potential predictors and mediators of activity in girls participating in the Trial of Activity in Adolescent Girls (TAAG). RESULTS: We found that the TAAG intervention had a statistically significant and positive effect on out of school activity in the 2006 cohort. Self-efficacy, friends' social support, total social support, and difficulty getting to and from community activities mediated the level of moderate to vigorous physical activity in girls. CONCLUSIONS: Parents, communities, and schools should provide and enhance opportunities outside of the school day for adolescents to be active. Reducing transportation barriers and enlisting social support appear to be key.

Maintenance of weight loss in overweight middle-aged women through the Internet.

OBJECTIVE: The purpose of this study was to compare weight regain in a group of perimenopausal women (48.0+/-4.4 years old), randomized to a 12-month weight maintenance Internet intervention or to self-directed weight maintenance after a 4-month weight loss treatment. METHODS AND PROCEDURES: After a 4-month behavioral weight loss program, 135 women were randomized to either Internet or self-directed groups. The Internet group (n=66) used a website to gain information and complete logs concerning their weight, diet, and exercise progress over a 12-month follow-up. The 69 self-directed women had no contact with study staff. All women were measured for weight and body composition, and diet intake, and were interviewed using the 7-day physical activity questionnaires at baseline, 4 months, and 16 months. RESULTS: At the end of the 12-month follow-up, the Internet and self-directed groups had regained on average 0.4+/-5.0 kg and 0.6+/-4.0 kg, respectively (P=0.5). In within-group analyses, Internet diet-log entries were correlated with follow-up weight change (r=-0.29; P<0.05) and moderately with change in exercise energy expenditure (EEE; r=0.44; P<0.01). Follow-up weight change was not correlated with change in dietary intake. DISCUSSION: While significant weight loss was maintained over follow-up by both groups of women, Internet use did not surpass self-direction in helping to sustain weight loss. Among Internet users, Internet use was related to weight change and EEE.

Depressive symptoms and changes in body weight exert independent and site-specific effects on bone in postmenopausal women exercising for 1 year.

BACKGROUND: Lower bone mineral density (BMD) has been documented in clinically depressed populations, and depression is the second most common chronic medical condition in general medical practice. Therefore, the purpose of this study was to determine whether depressive symptoms, vitality, and body weight changes were related to 1-year BMD changes after accounting for covariates. METHODS: Healthy postmenopausal women (n=320; 40-65 years) were recruited, and 266 women completed the study. Participants were 3-10 years postmenopausal, sedentary, and either taking hormone replacement therapy (1-3.9 years) or not taking it (at least 1 year). Exclusion criteria were: current smoking status, history of fractures, low BMD, body mass index>32.9 or <19.0, or use of bone altering medications. Regional BMD was measured from dual-energy x-ray absorptiometry at baseline and 1 year. Self-reported depressive symptoms and vitality were measured using standard questionnaires. RESULTS: Both the vitality and depressive symptoms scores were related to BMD changes at the femur neck but not at the greater trochanter or spine. Weight change was a predictor of BMD changes in the trochanter and spine but not in the femoral neck. Weight change and vitality and/or depressive symptoms had differential and site-specific effects on BMD changes at the hip. Vitality and depressive symptoms related to femoral neck changes and weight change related to greater trochanter changes. CONCLUSIONS: The negative impact of depressive symptoms on BMD in this population of postmenopausal women was independent of body weight or other behavioral factors such as calcium compliance or exercise.

Exercise motivation, eating, and body image variables as predictors of weight control.

PURPOSE: This study investigated changes in psychosocial variables related to exercise, eating, and body image during a weight reduction program and evaluated their association with weight loss in middle-aged overweight and obese women up to 1 yr after intervention. METHODS: The 136 participants (age, 48.1 +/- 4.4 yr; weight, 30.6 +/- 5.6 kg x m(-2)) who completed the 4-month lifestyle weight reduction program (86% retention), losing -6.2 +/- 4.6% (P < 0.001) of their initial weight, were followed up for 12 additional months. Of these, 82% completed 16-month assessments (weight change, -5.5 +/- 7.7%, P < 0.001). Psychosocial variables were assessed by validated instruments in standardized conditions at baseline and after the intervention (4 months). RESULTS: Compared with 4-month assessments, body weight did not change at 16 months (P > 0.09). Changes in eating restraint, disinhibition, and hunger; exercise, self-efficacy, and intrinsic motivation; body shape concerns; and physical self-worth were associated with weight change at 4 months (P < 0.001, except hunger, P < 0.05). Baseline-adjusted 4-month scores in all psychosocial variables also predicted weight change from baseline to 16 months (P < 0.01), except hunger (P > 0.05). After controlling for 4-month weight change and other covariates, increases in exercise intrinsic motivation remained predictive of weight loss at 16 months (P < 0.05). Multiple linear regression showed that eating variables were significant and independent correlates of short-term weight change, whereas changes in exercise variables were stronger predictors of longer term weight outcomes. CONCLUSIONS: Results highlight the importance of cognitive processes during weight control and support the notion that initial focus on diet is associated with short-term weight loss, while change in exercise-related motivational factors, with a special emphasis on intrinsic sources of motivation (e.g., interest and enjoyment in exercise), play a more important role in longer term weight management.

Exercise frequency and calcium intake predict 4-year bone changes in postmenopausal women.

The aim of this study was to examine the association of exercise frequency and calcium intake (CI) with change in regional and total bone mineral density (BMD) in a group of postmenopausal women completing 4 years of progressive strength training. One hundred sixty-seven calcium-supplemented (800 mg/day) sedentary women (56.1+/-4.5 years) randomized to a progressive strength training exercise program or to control were followed for 4 years. Fifty-four percent of the women were using hormone therapy (HT) at baseline. At 1 year, controls were permitted to begin the exercise program (crossovers). The final sample included 23 controls, 55 crossovers, and 89 randomized exercisers. Exercisers were instructed to complete two sets of six to eight repetitions of exercises at 70-80% of one repetition maximum, three times weekly. BMD was measured at baseline and thereafter annually using dual-energy X-ray absorptiometry. Four-year percentage exercise frequency (ExFreq) averaged 26.8%+/-20.1% for crossovers (including the first year at 0%), and 50.4%+/-26.7% for exercisers. Four-year total CI averaged 1,635+/-367 mg/day and supplemental calcium intake, 711+/-174 mg/day. In adjusted multiple linear regression models, ExFreq was positively and significantly related to changes in femur trochanter (FT) and neck (FN), lumbar spine (LS), and total body (TB) BMD. Among HT users, FT BMD increased 1.5%, and FN and LS BMD, 1.2% (p<0.01) for each standard deviation (SD) of percentage ExFreq (29.5% or 0.9 days/week). HT non-users gained 1.9% and 2.3% BMD at FT and FN, respectively, (p<0.05) for every SD of CI. The significant, positive, association between BMD change and ExFreq supports the long-term usefulness of strength training exercise for the prevention of osteoporosis in postmenopausal women, especially HT users. The positive relationship of CI to change in BMD among postmenopausal women not using HT has clinical implications in light of recent evidence of an increased health risk associated with HT.

Pathways curriculum and family interventions to promote healthful eating and physical activity in American Indian schoolchildren.

BACKGROUND: Pathways, a multisite school-based study aimed at promoting healthful eating and increasing physical activity, was a randomized field trial including 1704 American Indian third to fifth grade students from 41 schools (21 intervention, 20 controls) in seven American Indian communities. METHODS: The intervention schools received four integrated components: a classroom curriculum, food service, physical activity, and family modules. The curriculum and family components were based on Social Learning Theory, American Indian concepts, and results from formative research. Process evaluation data were collected from teachers (n=235), students (n=585), and families. Knowledge, Attitudes, and Behavior Questionnaire data were collected from 1150 students including both intervention and controls. RESULTS: There were significant increases in knowledge and cultural identity in children in intervention compared to control schools with a significant retention of knowledge over the 3 years, based on the results of repeating the third and fourth grade test items in the fifth grade. Family members participated in Family Events and take-home activities, with fewer participating each year. CONCLUSION: A culturally appropriate school intervention can promote positive changes in knowledge, cultural identity, and self-reported healthful eating and physical activity in American Indian children and environmental change in school food service.

Pathways: lessons learned and future directions for school-based interventions among American Indians.

BACKGROUND: Pathways, a multicenter study to test the effect of a school-based program to prevent obesity in American Indian children, yielded many benefits and encountered many challenges. This paper explores what we have learned from this study and examines possible future directions. METHODS: Information presented in this paper is based on formative research, study results, and discussions with staff and investigators. RESULTS: Some of the lessons learned relate to having a strong relationship with the tribes, how best to engage the communities, the importance of formative research and achieving standardization in culturally diverse settings, how to incorporate cultural information into curricula, and the importance of family involvement. One of the strengths of the study was the collaborative process that teamed American Indian and non-American Indian investigators and staff. Researchers recognized that they must work in cooperation with research participants including their schools and communities to address challenges, to ensure accurate findings and analyses, and to share benefits. CONCLUSIONS: The lessons learned from Pathways offer valuable insights for researchers into successful approaches to the challenges inherent in research in American Indian communities, particularly in schools, and how to maximize the benefits of such a study.

Effects of exercise on bone mineral density in calcium-replete postmenopausal women with and without hormone replacement therapy.

Osteoporosis is a major public health concern. The combination of exercise, hormone replacement therapy, and calcium supplementation may have added benefits for improving bone mineral density compared to a single intervention. To test this notion, 320 healthy, non-smoking postmenopausal women, who did or did not use hormone replacement therapy (HRT), were randomized within groups to exercise or no exercise and followed for 12 months. All women received 800 mg calcium citrate supplements daily. Women who exercised performed supervised aerobic, weight-bearing and weight-lifting exercise, three times per week in community-based exercise facilities. Regional bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry. Women who used HRT, calcium, and exercised increased femoral neck, trochanteric and lumbar spine bone mineral density by approximately 1-2%. Trochanteric BMD was also significantly increased by approximately 1.0% in women who exercised and used calcium without HRT compared to a negligible change in women who used HRT and did not exercise. The results demonstrate that regional BMD can be improved with aerobic, weight-bearing activity combined with weight lifting at clinically relevant sites in postmenopausal women. The response was significant at more sites in women who used HRT, suggesting a greater benefit with hormone replacement and exercise compared to HRT alone.

Resistance training in postmenopausal women with and without hormone therapy.

PURPOSE: The main purpose of this study was to analyze the impact of a 1-yr resistance-training program on body composition and muscle strength in postmenopausal women, and to describe the impact of hormone replacement therapy (HRT) on body composition changes, with and without exercise. Secondarily, we wanted to study dose-response relationships between measures of program compliance and changes in primary outcomes. METHODS: Subjects were postmenopausal women (40-66 yr) randomly assigned to an exercise (EX) group (N = 117) and a nonexercise group (N = 116). The EX group participated in a 1 yr trainer-supervised resistance-training program, 60-75 min.d-1, 3 d.wk-1. Lean soft tissue (LST) and fat tissue (FT) changes were measured by dual-energy x-ray absorptiometry and strength by one-repetition maximum testing. RESULTS: Significant (P < 0.001) gains in LST were observed for women who exercised, regardless of HRT status, whereas women who did not exercise lost LST (P < 0.05) if they were not taking HRT, and gained LST (P = 0.08) if they were on HRT. The only significant FT losses were observed for women who exercised while on HRT (P < 0.05). Strength increases were observed at all sites (P < 0.001). Total weight lifted by subjects in their training sessions was a significant predictor of changes in LST (P < 0.001) and strength (P < 0.01). CONCLUSIONS: Resistance and weight-bearing exercise significantly changed total and regional body composition in postmenopausal women by increasing LST in all women and decreasing FT in women on HRT. Hormone therapy showed no independent effects on body composition, but it protected nonexercising women from losses in LST. The lean and muscle strength changes observed were partially dependent on the volume of training, as expressed by attendance and total weight lifted in 1 yr of training.

Weight lifted in strength training predicts bone change in postmenopausal women.

PURPOSE: The aim of this study was to examine the relationship between weight lifted in 1 yr of progressive strength training and change in bone mineral density (BMD) in a group of calcium-replete, postmenopausal women. METHODS: As part of a large clinical trial, 140 calcium-supplemented women, 44-66 yr old, were randomized to a 1-yr progressive strength-training program. Half of the women were using hormone replacement therapy. Three times weekly, subjects completed two sets of six to eight repetitions in eight core exercises at 70-80% of one repetition maximum. BMD was measured at baseline and 1 yr. RESULTS: In multiple linear regression, the increase in femur trochanter (FT) BMD was positively related to total weight lifted (0.001 g.cm (-2)) for a SD of weight lifted, P< 0.01) after adjusting for age, baseline factors, HRT status, weight change, cohort, and fitness center. The weighted squats showed the strongest (0.002 g.cm(-2)) for a SD of weight lifted, P< 0.001), whereas the back extension exhibited the weakest (0.0005 g.cm(-2)) for a SD of weight lifted, P< 0.26) association with change in FT BMD. The amount of weight lifted in the weighted march exercise was significantly related to total body BMD (0.0006 g.cm(-2)) for a SD of weight lifted, P< 0.01). The associations between weight lifted and BMD for the femur neck or lumbar spine were not significant. CONCLUSION: Evidence of a linear relationship between BMD change and total and exercise-specific weight lifted in a 1-yr strength-training program reinforces the positive association between this type of exercise and BMD in postmenopausal women.

Weight loss readiness in middle-aged women: psychosocial predictors of success for behavioral weight reduction.

Accurate prediction of weight loss success and failure has eluded researchers for many years. Thus, we administered a comprehensive psychometric battery before a 4-month lifestyle behavioral weight reduction program and analyzed weight changes during that period to identify baseline characteristics of successful and unsuccessful participants, among 112 overweight and obese middle-aged women (age, 47.8 +/- 4.4 years; BMI, 31.4 +/- 3.9 kg/m2). Mean weight and percentage fat losses among the 89 completers were -5.4 kg and -3.4%, respectively (p < .001). A higher number of recent dieting attempts and recent weight loss, more stringent weight outcome evaluations, a higher perceived negative impact of weight on quality of life, lower self-motivation, higher body size dissatisfaction, and lower self-esteem were associated with less weight loss and significantly distinguished responders from nonresponders among all participants. These findings are discussed as to their usefulness (i) to screen individuals before treatment, (ii) to provide a better match between interventions to participants, and (iii) to build a weight loss readiness questionnaire.